thw wrote:But now I need to autostart it after complete boot. A .desktop file in the /etc/xdg/autostart is not working.

What desktop environment / window manager are you running? It sounds like this is not going to be an interactive unit, but a completely passive unit, and so you elected to not use Sugar, but something else? Gnome? KDE? XFCE? Using those as google guides may net you what you are looking for.